Put the rock candy, vanilla beans and raspberries in a large preserving jar (3 or 5 liters) and leave to infuse overnight.
The next day, add the vodka. Seal the jar and place on the windowsill for at least 4 weeks (but preferably 12 weeks). Shake once a day.
After 4-12 weeks, filter the mixture through a filter cloth and bottle the liqueur.